1. Technical Field
The present invention relates to an information terminal device which includes a touch panel having a touch input function on a display unit, and in particular, to an information terminal device that is further provided with operation buttons of such as push type around the display unit in addition to the touch panel.
2. Related Art
In recent years, portable information terminal devices such as PDAs and tablet PCs have been spreading rapidly. It is difficult to use a keyboard and a mouse with such a portable information terminal device, due to demands for improved usability as well as size and weight reduction. Accordingly, many information terminal devices are provided with a touch panel having transparent thin film electrodes (operation keys) provided so as to overlap a display unit, and are configured such that an input operation is carried out by a stylus or a finger on the operation keys displayed on the display unit.
While the finger input is convenient, the finger touching the touch panel makes a surface of the touch panel smudgy and reduces visibility of the touch panel. Accordingly, cleaning of the smudge on the surface of the touch panel is required. Further, as the smudge of the touch panel is contaminated and unsanitary, it is necessary to clean and sterilize the touch panel on a regular basis when the information terminal devices are used in medical institutions such as hospitals.
When cleaning the touch panel, in order to prevent malfunction, it is necessary to turn off a power switch so as to prohibit inputs from keys. However, as the touch panel is a transparent sheet and the smudge is not easily noticeable, it is not easy to recognize whether or not the smudge has been sufficiently wiped if the cleaning is carried out while the power is turned off. Therefore, an information terminal device has been proposed, for example, that is provided with a cleaning mode for cleaning the touch panel, and capable of, in the cleaning mode, disabling inputs from operation keys of the touch panel while the power is turned on, showing an entire area of the display unit in a single color, and detecting a portion that has been wiped and clearing the single color or turning into a different color, thereby making the wiped portion to be recognizable.
In this case, the information terminal device disclosed in JP-A-2000-194504 sets a time period of the cleaning mode to a predetermined time period, and disables inputs from operation keys until the set predetermined time period lapses when the cleaning mode is selected by the user, thereby preventing malfunction.
However, since the information terminal device described in JP-A-2000-194504 does not consider a degree of wiping, when the predetermined time period of the cleaning mode for a switch having large number of times of touching and large degree of smudge is short, there is often a case in which the smudge cannot be sufficiently removed by the wiping of this predetermined time period. Further, information terminal devices of this type are often provided with push type operation buttons such as the power switch around the display unit, but the conventional information terminal devices have not considered cleaning of the operation buttons provided around the display unit.